Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China.
Anal Chim Acta. 2011 Jan 17;684(1-2):121-5. doi: 10.1016/j.aca.2010.10.038. Epub 2010 Nov 4.
A highly sensitive and selective electrochemiluminescent (ECL) biosensor for the determination of adenosine was developed. Single DNA (capture DNA) was immobilized on the gold electrode through Au-thiol interaction at first. Another DNA modified with tris(2,2'-bipyridyl) ruthenium(II)-doped silica nanoparticles (Ru-SNPs) that contained adenosine aptamer was then modified on the electrode surface through hybridizing with the capture DNA. In the presence of adenosine, adenosine-aptamer complex is produced rather than aptamer-DNA duplex, resulting with the dissociation of Ru-SNPs-labeled aptamer from the electrode surface and the decrease in the ECL intensity. The decrease of ECL intensity has a direct relationship with the logarithm of adenosine concentration in the range of 1.0×10(-10) to 5.0×10(-6)molL(-1). The detection limit of the proposed method is 3.0×10(-11)molL(-1). The existence of guanosine, cytidine and uridine has little interference with adenosine detection, demonstrating that the developed biosensor owns a high selectivity to adenosine. In addition, the developed biosensor also demonstrates very good reusability, as after being reused for 30 times, its ECL signal still keeps 91% of its original state.
一种用于测定腺苷的高灵敏和选择性电化学发光（ECL）生物传感器被开发出来。首先，通过 Au-SH 相互作用将单链 DNA（捕获 DNA）固定在金电极上。然后，将另一种修饰有三（2,2'-联吡啶）钌（II）掺杂的硅纳米粒子（Ru-SNPs）的 DNA 通过与捕获 DNA 杂交修饰在电极表面上，该 DNA 修饰物含有腺苷适体。在存在腺苷的情况下，会产生腺苷-适体复合物，而不是适体-DNA 双链体，导致 Ru-SNPs 标记的适体从电极表面解离，ECL 强度降低。ECL 强度的降低与腺苷浓度在 1.0×10(-10) 至 5.0×10(-6)molL(-1)范围内的对数呈直接关系。该方法的检测限为 3.0×10(-11)molL(-1)。鸟嘌呤、胞嘧啶和尿嘧啶的存在对腺苷检测几乎没有干扰，表明所开发的生物传感器对腺苷具有高选择性。此外，所开发的生物传感器还表现出非常好的可重复使用性，在重复使用 30 次后，其 ECL 信号仍保持其原始状态的 91%。
